Study of potential drug-drug interactions between benzodiazepines and four commonly used antiepileptic drugs in mice.

ABSTRACT

Background: Benzodiazepines (BZD) is one of the commonly used drug groups for certain neurological diseases. As sometimes, the anti-epileptic drugs (AEDs) may be used concomitantly with BZD there is a potential for drug-drug interactions. Study aimed to study potential drug-drug interactions between four commonly used AEDs (phenytoin, carbamazepine (CBZ), phenobarbitone, sodium valproate) and BZD (diazepam, clonazepam) in mice using maximal electroshock seizure (MES) method and pentylenetetrazole (PTZ) method. Methods: Adult male albino mice were divided into four different groups of six animals each and anti-epileptic activity was assessed using MES method and PTZ method. Group I acted as a control, Group II received any one of the four AEDs (phenytoin, CBZ, phenobarbitone or sodium valproate) in sub-effective doses, Group III received diazepam or clonazepam alone, Group IV received a combination of diazepam or clonazepam with any one of the AEDs. Results: In MES method, the groups receiving combination of diazepam with phenytoin and CBZ showed significant protection compared to the control group (p<0.01 and p<0.02), respectively. However, diazepam in combination with sodium valproate and phenobarbitone did not show any significant protection compared to the control group and individual antiepileptic group. All the four antiepileptic showed significant protection against MES seizure in combination with clonazepam when compared to control group. In PTZ method, combination of sodium valproate with clonazepam showed significant protection compared to control group (p<0.02). However, this was not observed with diazepam-valproate combination. Conclusion: Clonazepam potentiates the action of all the four anti-epileptics while diazepam potentiates only phenytoin and CBZ against MES seizures. Clonazepam but not diazepam potentiates the action of sodium valproate against PTZ seizures.